System and method for transmitting a signal

ABSTRACT

A system and method for allocating network resources are disclosed herein. In one embodiment, the system and method are configured to perform: receiving a resource allocation message indicative of a plurality of resource groups allocated for a signal; and transmitting the signal using a portion of the plurality of resource groups, wherein, in a frequency domain, the portion of the plurality of resource groups presents a hopping pattern comprising at least a first hopping path that is associated with a first plurality of increasing frequency spacings and a second hopping path that is associated with a second plurality of decreasing frequency spacings.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.16/739,020, filed on Jan. 9, 2020, which claims priority to PCTinternational application PCT/CN2017/092813, entitled “SYSTEM AND METHODFOR TRANSMITTING A SIGNAL,” filed on Jul. 13, 2017, each of which isexpressly incorporated by reference herein in its entirety.

TECHNICAL FIELD

The disclosure relates generally to wireless communications and, moreparticularly, to systems and methods for allocating resource to transmita signal.

BACKGROUND

In accordance with rapid developments and increasing needs of theInternet of Things (IoT), a new radio interface, a Narrowband Internetof Things (NB-IoT), has been proposed by the 3^(rd) GenerationPartnership Project (3GPP). The NB-IoT is aimed to enhance existingGlobal System for Mobile Communications (GSM) and Long-Term Evolution(LTE) networks to better serve IoT uses or applications. Improved indoorcoverage, support for massive number of low throughput end devices, lowdelay sensitivity, ultra-low device cost, coverage extension, batterylifetime extension, and backward compatibility are some exemplaryobjectives of the NB-IoT.

Generally, in a wireless communication system adopting the NB-IoT(hereinafter “NB-IoT system”), a user equipment device (UE) sends atleast one preamble signal (hereinafter “Preamble’), typically via aPhysical Random Access Channel (PRACH), to a base station (BS) toinitiate a contention-based random access procedure. Such a Preamble isused as a temporary identity of the UE for the BS to estimate variousinformation, e.g., timing advance command, scheduling of uplinkresources for the UE to use in subsequent steps, such that the UE mayuse the above-mentioned information to finish the random accessprocedure.

An existing format of the Preamble includes a first set of four symbolgroups (SGs) that are adjacent to one another in a time domain andsubjected to only one frequency hopping over more than two subcarrierindexes in a frequency domain. The Preamble is sent using the first setof the four SGs, and when the Preamble is desired to be sent again oranother Preamble is desired to be sent, a second set of four SGs,limited by the same criteria as described above, is used. Moreover, inthe existing format of the Preamble, the first and second sets of SGs,for example, are randomly chosen from a pre-defined pattern, wherein thepattern is formed by a plurality of SGs that are confined within 12subcarriers in the frequency domain.

However, it has been noted that the use of the existing format of thePreamble may encounter a variety of issues such as, for example, wrongestimation of the timing advance command when a respective coverage ofthe BS extends beyond 100 kilometers (typically known as a “cell”),strong interference among plural neighboring cells, etc. Accordingly,the existing format of the Preamble in the NB-IoT system is not entirelysatisfactory.

SUMMARY OF THE INVENTION

The exemplary embodiments disclosed herein are directed to solving theissues relating to one or more of the problems presented in the priorart, as well as providing additional features that will become readilyapparent by reference to the following detailed description when takenin conjunction with the accompany drawings. In accordance with variousembodiments, exemplary systems, methods, devices and computer programproducts are disclosed herein. It is understood, however, that theseembodiments are presented by way of example and not limitation, and itwill be apparent to those of ordinary skill in the art who read thepresent disclosure that various modifications to the disclosedembodiments can be made while remaining within the scope of theinvention.

In one embodiment, a method includes: receiving a resource allocationmessage indicative of a plurality of resource groups allocated for asignal; and transmitting the signal using a portion of the plurality ofresource groups, wherein, in a frequency domain, the portion of theplurality of resource groups presents a hopping pattern comprising atleast a first hopping path that is associated with a first plurality ofincreasing frequency spacings and a second hopping path that isassociated with a second plurality of decreasing frequency spacings.

In a further embodiment, a method includes: transmitting a resourceallocation message indicating a plurality of resource groups allocatedfor a signal, wherein, in a frequency domain, at least a portion of theplurality of resource groups presents a hopping pattern comprising atleast a first hopping path that is associated with a first plurality ofincreasing frequency spacings and a second hopping path that isassociated with a second plurality of decreasing frequency spacings.

In another embodiment, a communication node includes: a receiverconfigured to receive a resource allocation message indicative of aplurality of resource groups allocated for a signal; and a transmitterconfigured to transmit the signal using a portion of the plurality ofresource groups. In a frequency domain, the portion of the plurality ofresource groups presents a hopping pattern comprising at least a firsthopping path that is associated with a first plurality of increasingfrequency spacings and a second hopping path that is associated with asecond plurality of decreasing frequency spacings.

In yet another embodiment, a communication node, includes: a transmitterconfigured to transmit a resource allocation message indicating aplurality of resource groups allocated for a signal. In a frequencydomain, at least a portion of the plurality of resource groups presentsa hopping pattern comprising at least a first hopping path that isassociated with a first plurality of increasing frequency spacings and asecond hopping path that is associated with a second plurality ofdecreasing frequency spacings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various exemplary embodiments of the invention are described in detailbelow with reference to the following Figures. The drawings are providedfor purposes of illustration only and merely depict exemplaryembodiments of the invention to facilitate the reader's understanding ofthe invention. Therefore, the drawings should not be considered limitingof the breadth, scope, or applicability of the invention. It should benoted that for clarity and ease of illustration these drawings are notnecessarily drawn to scale.

FIG. 1 illustrates an exemplary cellular communication network in whichtechniques disclosed herein may be implemented, in accordance with anembodiment of the present disclosure.

FIG. 2 illustrates block diagrams of an exemplary base station and auser equipment device, in accordance with some embodiments of thepresent disclosure.

FIG. 3A illustrates an exemplary frame structure of a symbol group, inaccordance with some embodiments of the present disclosure.

FIG. 3B illustrates another exemplary frame structure of a symbol group,in accordance with some embodiments of the present disclosure.

FIG. 4A illustrates an exemplary symbol group map, in accordance withsome embodiments of the present disclosure.

FIGS. 4B and 4C respectively illustrate exemplary formats of a preamblesignal when the symbol group map of FIG. 4A is used, in accordance withsome embodiments of the present disclosure.

FIG. 5A illustrates another exemplary symbol group map, in accordancewith some embodiments of the present disclosure.

FIGS. 5B and 5C respectively illustrate exemplary formats of a preamblesignal when the symbol group map of FIG. 5A is used, in accordance withsome embodiments of the present disclosure.

FIG. 6A illustrates yet another exemplary symbol group map, inaccordance with some embodiments of the present disclosure.

FIG. 6B illustrates an exemplary format of a preamble signal when thesymbol group map of FIG. 6A is used, in accordance with some embodimentsof the present disclosure.

FIG. 7A illustrates yet another exemplary symbol group map, inaccordance with some embodiments of the present disclosure.

FIG. 7B illustrates an exemplary format of a preamble signal when thesymbol group map of FIG. 7A is used, in accordance with some embodimentsof the present disclosure.

FIG. 8A illustrates yet another exemplary symbol group map, inaccordance with some embodiments of the present disclosure.

FIG. 8B illustrates an exemplary format of a preamble signal when thesymbol group map of FIG. 8A is used, in accordance with some embodimentsof the present disclosure.

FIG. 9 illustrates a flow chart of an exemplary method to assign a valueto symbols of a symbol group, in accordance with some embodiments of thepresent disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Various exemplary embodiments of the invention are described below withreference to the accompanying figures to enable a person of ordinaryskill in the art to make and use the invention. As would be apparent tothose of ordinary skill in the art, after reading the presentdisclosure, various changes or modifications to the examples describedherein can be made without departing from the scope of the invention.Thus, the present invention is not limited to the exemplary embodimentsand applications described and illustrated herein. Additionally, thespecific order or hierarchy of steps in the methods disclosed herein aremerely exemplary approaches. Based upon design preferences, the specificorder or hierarchy of steps of the disclosed methods or processes can bere-arranged while remaining within the scope of the present invention.Thus, those of ordinary skill in the art will understand that themethods and techniques disclosed herein present various steps or acts ina sample order, and the invention is not limited to the specific orderor hierarchy presented unless expressly stated otherwise.

FIG. 1 illustrates an exemplary wireless communication network 100 inwhich techniques disclosed herein may be implemented, in accordance withan embodiment of the present disclosure. In the following discussion,the wireless communication network 100 may be a NB-IoT network, which isherein referred to as “network 100.” Such an exemplary network 100includes a base station 102 (hereinafter “BS 102”) and a user equipmentdevice 104 (hereinafter “UE 104”) that can communicate with each othervia a communication link 110 (e.g., a wireless communication channel),and a cluster of notional cells 126, 130, 132, 134, 136, 138 and 140overlaying a geographical area 101. In FIG. 1, the BS 102 and UE 104 arecontained within a respective geographic boundary of cell 126. Each ofthe other cells 130, 132, 134, 136, 138 and 140 may include at least onebase station operating at its allocated bandwidth to provide adequateradio coverage to its intended users.

For example, the BS 102 may operate at an allocated channel transmissionbandwidth to provide adequate coverage to the UE 104. The BS 102 and theUE 104 may communicate via a downlink radio frame 118, and an uplinkradio frame 124 respectively. Each radio frame 118/124 may be furtherdivided into sub-frames 120/127 which may include data symbols 122/128.In the present disclosure, the BS 102 and UE 104 are described herein asnon-limiting examples of “communication nodes,” generally, which canpractice the methods disclosed herein. Such communication nodes may becapable of wireless and/or wired communications, in accordance withvarious embodiments of the invention.

FIG. 2 illustrates a block diagram of an exemplary wirelesscommunication system 200 for transmitting and receiving wirelesscommunication signals, e.g., OFDM/OFDMA signals, in accordance with someembodiments of the invention. The system 200 may include components andelements configured to support known or conventional operating featuresthat need not be described in detail herein. In one exemplaryembodiment, system 200 can be used to transmit and receive data symbolsin a wireless communication environment such as the wirelesscommunication environment 100 of FIG. 1, as described above.

System 200 generally includes a base station 202 (hereinafter “BS 202”)and a user equipment device 204 (hereinafter “UE 204”). The BS 202includes a BS (base station) transceiver module 210, a BS antenna 212, aBS processor module 214, a BS memory module 216, and a networkcommunication module 218, each module being coupled and interconnectedwith one another as necessary via a date communication bus 220. The UE204 includes a UE (user equipment) transceiver module 230, a UE antenna232, a UE memory module 234, and a UE processor module 236, each modulebeing coupled and interconnected with one another as necessary via adata communication bus 240. The BS 202 communicates with the UE 204 viaa communication channel 250, which can be any wireless channel or othermedium known in the art suitable for transmission of data as describedherein.

As would be understood by persons of ordinary skill in the art, system200 may further include any number of modules other than the modulesshown in FIG. 2. Those skilled in the art will understand that thevarious illustrative blocks, modules, circuits, and processing logicdescribed in connection with the embodiments disclosed herein may beimplemented in hardware, computer-readable software, firmware, or anypractical combination thereof. To clearly illustrate thisinterchangeability and compatibility of hardware, firmware, andsoftware, various illustrative components, blocks, modules, circuits,and steps are described generally in terms of their functionality.Whether such functionality is implemented as hardware, firmware, orsoftware depends upon the particular application and design constraintsimposed on the overall system. Those familiar with the conceptsdescribed herein may implement such functionality in a suitable mannerfor each particular application, but such implementation decisionsshould not be interpreted as limiting the scope of the presentinvention.

In accordance with some embodiments, the UE transceiver 230 may bereferred to herein as an “uplink” transceiver 230 that includes a RFtransmitter and receiver circuitry that are each coupled to the antenna232. A duplex switch (not shown) may alternatively couple the uplinktransmitter or receiver to the uplink antenna in time duplex fashion.Similarly, in accordance with some embodiments, the BS transceiver 210may be referred to herein as a “downlink” transceiver 210 that includesRF transmitter and receiver circuitry that are each coupled to theantenna 212. A downlink duplex switch may alternatively couple thedownlink transmitter or receiver to the downlink antenna 212 in timeduplex fashion. The operations of the two transceivers 210 and 230 arecoordinated in time such that the uplink receiver is coupled to theuplink antenna 232 for reception of transmissions over the wirelesstransmission link 250 at the same time that the downlink transmitter iscoupled to the downlink antenna 212. Preferably there is close timesynchronization with only a minimal guard time between changes in duplexdirection.

The UE transceiver 230 and the base station transceiver 210 areconfigured to communicate via the wireless data communication link 250,and cooperate with a suitably configured RF antenna arrangement 212/232that can support a particular wireless communication protocol andmodulation scheme. In some exemplary embodiments, the UE transceiver 210and the base station transceiver 210 are configured to support industrystandards such as the Long Term Evolution (LTE) and emerging 5Gstandards, and the like. It is understood, however, that the inventionis not necessarily limited in application to a particular standard andassociated protocols. Rather, the UE transceiver 230 and the basestation transceiver 210 may be configured to support alternate, oradditional, wireless data communication protocols, including futurestandards or variations thereof.

In accordance with various embodiments, the BS 202 may be an evolvednode B (eNB), a serving eNB, a target eNB, a femto station, or a picostation, for example. In some embodiments, the UE 204 may be embodied invarious types of user devices such as a mobile phone, a smart phone, apersonal digital assistant (PDA), tablet, laptop computer, wearablecomputing device, etc. The processor modules 214 and 236 may beimplemented, or realized, with a general purpose processor, a contentaddressable memory, a digital signal processor, an application specificintegrated circuit, a field programmable gate array, any suitableprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof, designed to perform thefunctions described herein. In this manner, a processor may be realizedas a microprocessor, a controller, a microcontroller, a state machine,or the like. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a digital signal processor anda microprocessor, a plurality of microprocessors, one or moremicroprocessors in conjunction with a digital signal processor core, orany other such configuration.

Furthermore, the steps of a method or algorithm described in connectionwith the embodiments disclosed herein may be embodied directly inhardware, in firmware, in a software module executed by processormodules 214 and 236, respectively, or in any practical combinationthereof. The memory modules 216 and 234 may be realized as RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a harddisk, a removable disk, a CD-ROM, or any other form of storage mediumknown in the art. In this regard, memory modules 216 and 234 may becoupled to the processor modules 210 and 230, respectively, such thatthe processors modules 210 and 230 can read information from, and writeinformation to, memory modules 216 and 234, respectively. The memorymodules 216 and 234 may also be integrated into their respectiveprocessor modules 210 and 230. In some embodiments, the memory modules216 and 234 may each include a cache memory for storing temporaryvariables or other intermediate information during execution ofinstructions to be executed by processor modules 210 and 230,respectively. Memory modules 216 and 234 may also each includenon-volatile memory for storing instructions to be executed by theprocessor modules 210 and 230, respectively.

The network communication module 218 generally represents the hardware,software, firmware, processing logic, and/or other components of thebase station 202 that enable bi-directional communication between basestation transceiver 210 and other network components and communicationnodes configured to communication with the base station 202. Forexample, network communication module 218 may be configured to supportinternet or WiMAX traffic. In a typical deployment, without limitation,network communication module 218 provides an 802.3 Ethernet interfacesuch that base station transceiver 210 can communicate with aconventional Ethernet based computer network. In this manner, thenetwork communication module 218 may include a physical interface forconnection to the computer network (e.g., Mobile Switching Center(MSC)).

Referring again to FIG. 1, as discussed above, to initiate a randomaccess procedure, the UE 104 sends a Preamble using a plurality ofresource groups (e.g., SGs (symbol groups)) to the BS 102. The presentdisclosure provides various embodiments of a format of such a Preamble,hereinafter the “Preamble format,” for the UE 104 to use. In someembodiments, the disclosed Preamble format includes a plurality of SGpatterns, each of which is subjected to a respective frequency/timehopping rule. In some embodiments, such frequency/time hopping rule maybe pre-defined in a protocol of the network 100 or transmitted in ahigher-level signal (e.g., a radio resource control (RRC) signal) fromthe BS 102 to the UE 104. Compared to the existing Preamble format, therespective frequency/time hopping rules advantageously allows the BS 102to estimate the timing advanced command more accurately for the UE 104(i.e., more accurate scheduling), for example, when the cell 126 isimplanted as a cell that has a coverage greater than 100 kilometers(kin), which will be discussed below. Moreover, when using thefrequency/time hopping rules to send a Preamble, interference betweenthe cell 126 and one or more other neighboring cells (e.g., 130, 132,136, etc.) may be substantially mitigated, which can in turn reduce aFalse Alarm Probability (FAP) happening to the Preamble.

FIGS. 3A and 3B provide two exemplary frame structures of the SG 302 and304, respectively, that can be used by the disclosed Preamble format, inaccordance with some embodiments of the present disclosure. Referringfirst to FIG. 3A, the SG 302 includes a cyclic prefix (CP) 302-1, andthree symbols (Ss) 302-2, 302-3, and 302-4. More specifically, each ofthe symbols in the SG 302 extends across a time duration of about 266.7microseconds (μs) and the CP 302-1 extends across 3 of such a timeduration of the symbol (i.e., 3×266.7 μs) along the time domain, and ismodulated on a 3.75 kHz tone along the frequency domain, e.g., a 3.75kHz frequency spacing, which is typically known as a 3.75 kHz subcarrierspacing. For purpose of consistency, the SG 302 is herein referred to asbeing defined on a 3.75 kHz subcarrier spacing. As such, the SG 302 mayextend across about 1.6 milliseconds (ms) in the time domain and spacedfrom another SG by 3.75 kHz in the frequency domain.

Referring then to FIG. 3B, the SG 304 includes one CP 304-1, and twosymbols 304-2 and 304-3. More specifically, each of the CP and symbolsin the SG 304 extends across a time duration of about 800 μs along thetime domain, and is modulated on a 1.25 kHz tone along the frequencydomain, e.g., a 1.25 kHz subcarrier spacing, which is typically known asa 1.25 kHz subcarrier spacing. For purpose of consistency, the SG 304 isherein referred to as being defined on a 1.25 kHz subcarrier spacing. Assuch, the SG 304 may extend across about 2.4 milliseconds (ms) in thetime domain and spaced from another SG by 1.25 kHz in the frequencydomain. It is noted that the frame structures of the SG 302 and 304, ofFIGS. 3A and 3B, are merely provided for illustration purposes.Accordingly, any of a variety of other frame structures of the SG can beused in the following discussions of the disclosed Preamble format whileremaining within the scope of the present disclosure. For example, theSG frame structure may have any desired length (e.g., time duration) ofCP(s) and any desired number of symbol(s), respectively, and/or bemodulated on any desired frequency of tone (i.e., having any desiredfrequency/subcarrier spacing).

In an embodiment, when an SG is defined based on the subcarrier spacingof 3.75 kHz (e.g., the SG 302), a disclosed Preamble format, which willbe discussed with respect to FIGS. 4B and 4C, is decided based on apre-defined SG map 400 as illustrated in FIG. 4A. In the illustratedembodiment of FIG. 4A, the SG map 400 includes 96 SGs, each of which maybe implemented by the SG 302. More specifically, in some embodiments,the SG map 400 extends across 8 SGs with corresponding time durations(12.8 ms) in the time domain, and across 12 SGs, i.e., 12 contiguoussubcarrier spacings, in the frequency domain (180 kHz), respectively. Inthe time domain, each SG is associated with a respective SG index (e.g.,SG index 1, 2, 3, 4, 5, 6, 7, or 8); and in the frequency domain, eachSG is associated with a respective frequency index, for example, arespective subcarrier index (e.g., subcarrier index 0, 1, 2, 3, 4, 5, 6,7, 8, 9, 10, or 11). In some embodiments, the first 4 SGs (i.e., the SGswith SG indexes 1-4) and last 4 SGs (i.e., the SGs with SG indexes 5-8)of the SG map 400 may be spaced from each other by a pre-defined timeinterval.

According to some embodiments, the SG map 400 are divided into twosub-groups 401 and 403, which are filled with a dotted pattern and adiagonal stripes pattern, respectively, as shown in FIG. 4A. In someembodiments, in the SG map 400, the SGs sharing a common SG index (i.e.,along a same column of the SG map 400) has a half that belongs to thesub-group 401 and the other half that belongs to the sub-group 403.Further, along one of the columns of the SG map 400, each of the SGs,belonging to the sub-group 401, is associated with a respective PRACH(Physical Random Access Channel) index that is selected from one of 0,1, 2, 3, 4, and 5; and each of the SGs, belonging to the sub-group 403,is associated with a respective PRACH index that is selected from one of0, 1, 2, 3, 4, and 5. In some embodiments, respective distributions ofthe PRACH indexes in terms of SG index/subcarrier index within eachsub-group are pre-defined, as provided below.

For example, along the column with the SG index 1, the SGs within thesub-group 401 with the subcarrier indexes 0, 1, 2, 3, 4, and 5 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; and the SGs within the sub-group 403 with the subcarrierindexes 6, 7, 8, 9, 10, and 11 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively. Along the column with the SGindex 2, the SGs within the sub-group 401 with the subcarrier indexes 0,1, 2, 3, 4, and 5 are associated with respective PRACH indexes 1, 0, 3,2, 5, and 4, respectively; and the SGs within the sub-group 403 with thesubcarrier indexes 6, 7, 8, 9, 10, and 11 are associated with respectivePRACH indexes 1, 0, 3, 2, 5, and 4, respectively. Along the column withthe SG index 3, the SGs within the sub-group 403 with the subcarrierindexes 0, 1, 2, 3, 4, and 5 are associated with respective PRACHindexes 1, 0, 3, 2, 5, and 4, respectively; and the SGs within thesub-group 401 with the subcarrier indexes 6, 7, 8, 9, 10, and 11 areassociated with respective PRACH indexes 1, 0, 3, 2, 5, and 4,respectively. Along the column with the SG index 4, the SGs within thesub-group 403 with the subcarrier indexes 0, 1, 2, 3, 4, and 5 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; and the SGs within the sub-group 401 with the subcarrierindexes 6, 7, 8, 9, 10, and 11 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively. Along the column with the SGindex 5, the SGs within the sub-group 403 with the subcarrier indexes 0,1, 2, 3, 4, and 5 are associated with respective PRACH indexes 1, 0, 3,2, 5, and 4, respectively; and the SGs within the sub-group 401 with thesubcarrier indexes 6, 7, 8, 9, 10, and 11 are associated with respectivePRACH indexes 1, 0, 3, 2, 5, and 4, respectively. Along the column withthe SG index 6, the SGs within the sub-group 403 with the subcarrierindexes 0, 1, 2, 3, 4, and 5 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively; and the SGs within thesub-group 401 with the subcarrier indexes 6, 7, 8, 9, 10, and 11 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively. Along the column with the SG index 7, the SGs within thesub-group 401 with the subcarrier indexes 0, 1, 2, 3, 4, and 5 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; and the SGs within the sub-group 403 with the subcarrierindexes 6, 7, 8, 9, 10, and 11 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively. Along the column with the SGindex 8, the SGs within the sub-group 401 with the subcarrier indexes 0,1, 2, 3, 4, and 5 are associated with respective PRACH indexes 1, 0, 3,2, 5, and 4, respectively; and the SGs within the sub-group 403 with thesubcarrier indexes 6, 7, 8, 9, 10, and 11 are associated with respectivePRACH indexes 1, 0, 3, 2, 5, and 4, respectively.

The above-discussed distribution of PRACH indexes of the SG map 400 ispre-defined in accordance with a first frequency/time hopping rule thatcan be used by a UE (e.g., 104 of FIG. 1) to send a Preamble to a BS(e.g., 102 of FIG. 1) for initiating a random access procedure, inaccordance with some embodiments. In accordance with some embodiments ofthe present disclosure, the first frequency/time hopping rule indicatesthat the Preamble is sent using at least 8 SGs (i.e., the Preambleincludes at least 8 SGs), each of which is selected from a respective SGindex. Further, the first frequency/time hopping rule indicates thateither the sub-group 401 or 403 is selected, and subsequently, a firstSG can be randomly chosen from the first column (i.e., the column withthe SG index 1) of the SG map 400 within the selected sub-group. Next,subsequent (e.g., remaining) SGs of the at least 8 SGs are each chosenfrom a respective column (i.e., the columns with SG indexes 2, 3, 4, 5,6, 7, and 8) within the selected sub-group, wherein all 8 SGs share asame PRACH index, or alternatively, a first set of 4 SGs shares a firstPRACH index and a second set of 4 SGs shares a second PRACH index.

In another embodiment, the first frequency/time hopping rule includes:randomly selecting an SG from the first column as the first SG of the atleast 8 SGs; based on a respective sub-carrier index of the randomlyselected SG in the first column, determining which of the sub-groups andwhich PRACH index to be used for the remaining 7 SGs of the at least 8SGs.

In yet another embodiment, the first frequency/time hopping ruleincludes: randomly selecting an SG from the first column as the first SGof the at least 8 SGs; based on a respective sub-carrier index of therandomly selected SG in the first column, determining which of thesub-groups and which PRACH index to be used for the second, third,fourth SGs of the at least 8 SGs; randomly selecting an SG from thefifth column as the fifth SG of the at least 8 SGs within the sub-groupthat is selected by the first SG; based on a respective sub-carrierindex of the randomly selected SG in the fifth column, determining whichof the sub-groups and which PRACH index to be used for the sixth,seventh, eighth SGs of the at least 8 SGs. More specifically, asub-carrier index of an (n+1)^(th) SG within the at least 8 SGs can bedetermined by one of the following equations (1) and (2)

$\begin{matrix}{{{\overset{˜}{n}}_{sc}^{RA}(i)} = \{ {{\begin{matrix}{{( {{{\overset{˜}{n}}_{sc}^{RA}(0)} + {f( {i/4} )}} ){mod}( {N_{sc}^{RA}/2} )} + {6 \cdot ( {( {i/4} ){mod}2} )}} & {{i\ {mod}4}\  = {{0\ {and}\ i} > {0\ {and}{\ }0} \leq {{\overset{˜}{n}}_{sc}^{RA}(0)} < 6}} \\{{ {{{\overset{˜}{( n }}_{sc}^{RA}(0)} + {f( {i/4} )}} ){mod}( {N_{sc}^{RA}/2} )} + {6 \cdot ( {( {{i/4} - 1} ){mod}2} )}} & {{i\ {mod}4}\  = {{0\ {and}\ i} > {0\ {and}{\ }6} \leq {{\overset{˜}{n}}_{sc}^{RA}(0)} < N_{sc}^{RA}}} \\{{{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} + 1} & {{{i\ {mod}4}\  = 1},{{3\ {and}{\overset{˜}{n}}_{sc}^{RA}( {i - 1} ){mod}2}\  = 0}} \\{{{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} - 1} & {{{i\ {mod}4}\  = 1},{{3\ {and}{\overset{˜}{n}}_{sc}^{RA}( {i - 1} ){mod}2}\  = 1}} \\{{{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} + 6} & {{i\ {mod}4}\  = {{2\ {and}{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} < 6}} \\{{{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} - 6} & {{i\ {mod}4}\  = {{2\ {and}{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} \geq 6}}\end{matrix}{f(t)}} = {{( {{f( {t - 1} )} + {( {\overset{{10t} + 9}{\sum\limits_{n = {{10t} + 1}}}{{c(n)}2^{n - {({{10t} + 1})}}}} ){{mod}\ ( {N_{sc}^{RA} - 1} )}} + 1} ){mod}\ N_{sc}^{RA}{f( {- 1} )}} = 0}} } & {{Equation}(1)}\end{matrix}$ $\begin{matrix}{{{\overset{˜}{n}}_{sc}^{RA}(i)} = \{ {{{\begin{matrix}{{( {{{\overset{˜}{n}}_{sc}^{RA}(0)} + {f( {i/4} )}} ){mod}( {N_{sc}^{RA}/2} )} + {6 \cdot ( {( {{i/4} + {{floor}( {{\overset{˜}{n}}_{sc}^{RA}(0)/6} )}} ){mod}2} )}} & {{i\ {mod}4}\  = {{0\ {and}\ i} > 0\ }} \\{{{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} + 1} & {{{i\ {mod}4}\  = 1},{{3\ {and}{\overset{˜}{n}}_{sc}^{RA}( {i - 1} ){mod}2}\  = 0}} \\{{{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} - 1} & {{{i\ {mod}4}\  = 1},{{3\ {and}{\overset{˜}{n}}_{sc}^{RA}( {i - 1} ){mod}2}\  = 1}} \\{{{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} + 6} & {{i\ {mod}4}\  = {{2\ {and}{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} < 6}} \\{{{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} - 6} & {{i\ {mod}4}\  = {{2\ {and}{\overset{˜}{n}}_{sc}^{RA}( {i - 1} )} \geq 6}}\end{matrix}{f(t)}} = {{( {{f( {t - 1} )} + {( {\overset{{10t} + 9}{\sum\limits_{n = {{10t} + 1}}}{{c(n)}2^{n - {({{10t} + 1})}}}} ){{mod}\ ( {N_{sc}^{RA} - 1} )}} + 1} ){mod}\ N_{sc}^{RA}{f( {- 1} )}} = 0}},} } & {{Equation}(2)}\end{matrix}$

whereinN_(sc) ^(RA) is the number of subcarrier spacings within the SG map 400,and N_(sc) ^(RA)=12;ñ_(SC) ^(RA)(i) is the sub-carrier index of the (i+1)^(th) SG within theN_(sc) ^(RA) subcarriers, i is an integer, and i≥0;

ñ_(SC) ^(RA)(0) is the selected sub-carrier index of the 1^(th) SG;

a pseudo random sequence c(n) is given as below:Pseudo-random sequences are defined by a length-31 Gold sequence. Theoutput sequence c(n) of length M_(PN), where n=0, 1, . . . , M_(PN)−1,is defined by

c(n) = (x₁(n + N_(C)) + x₂(n + N_(C)))mod2x₁(n + 31) = (x₁(n + 3) + x₁(n))mod2x₂(n + 31) = (x₂(n + 3) + x₂(n + 2) + x₂(n + 1)x₂(n))mod2

where N_(C)=1600 and the first m-sequence shall be initialized withx₁(0)=1,x₁(n)=0,n=1, 2, . . . , 30. The initialization of the secondm-sequence is denoted by c_(init)=Σ_(i=0) ³⁰x₂(i)·2^(i), and the pseudorandom sequence generator shall be initialized with

c_(init) = (32 ⋅ N_(ID)^(Ncell) + cc + 1)((1024 ⋅ n_(hf) + n_(f))mod 79 + 1)² ⋅ 2⁹ + 32 ⋅ N_(ID)^(Ncell) + cc.,

wherein,

N_(ID) ^(Ncell) is the Cell Identity (Cell ID);

cc is the component carrier index in which PRACH resource is allocated;

n_(hf) is the hyper frame index;

n_(f) is the frame index

As such, the Preamble follows a corresponding Preamble format when thefirst frequency/time hopping rule is applied.

In an embodiment, when the first frequency/time hopping rule is appliedand the Preamble is sent using more than 8 SGs, e.g., 16 SGs, respectivesubcarrier indexes of a first SG of a first set of 8 SGs and a first SGof a second set of 8 SGs may be randomly selected.

FIGS. 4B and 4C provide two exemplary Preamble formats 420 and 440 thatcan be used by a Preamble including at least 8 SGs when the firstfrequency/time hopping rule is applied. As mentioned above, one of thesub-groups 401 and 403 is selected. In FIG. 4B, the sub-group 401 isselected. Next, within the sub-group 401, a first SG with acorresponding subcarrier index is randomly chosen from the first column(the SG index=1) of the SG map 400. In an example, the subcarrier index“0” is chosen as the first SG from the first column, which causes thefirst SG to be associated with the PRACH index 0 (within the sub-group401). Following the first frequency/time hopping rule, each of theremaining 7 SGs is chosen from a respective column within the sub-group401 and having the same PRACH index as the first SG. As such, from thesecond column (the SG index=2), the SG with the subcarrier index “1” ischosen as a second SG since it is associated with the PRACH index 0;from the third column (the SG index=3), the SG with the subcarrier index“7” is chosen as a third SG since it is associated with the PRACH index0; from the fourth column (the SG index=4), the SG with the subcarrierindex “6” is chosen as a fourth SG since it is associated with the PRACHindex 0; from the fifth column (the SG index=5), the SG with thesubcarrier index “7” is chosen as a fifth SG since it is associated withthe PRACH index 0; from the sixth column (the SG index=6), the SG withthe subcarrier index “6” is chosen as a sixth SG since it is associatedwith the PRACH index 0; from the seventh column (the SG index=7), the SGwith the subcarrier index “0” is chosen as a seventh SG since it isassociated with the PRACH index 0; from the eighth column (the SGindex=8), the SG with the subcarrier index “1” is chosen as an eighth SGsince it is associated with the PRACH index 0.

In some embodiments, when using the first frequency/time hopping rule toprovide the Preamble format 420, the first SG with a subcarrier index,e.g., subcarrier index “k,” is chosen within the sub-group 401, whereink is randomly chosen and is 0 in the above example, and the remainingSGs (second, third, fourth, fifth, sixth, seventh, and eighth SGs) arechosen as follows. The second SG is chosen to hop “upwardly” from thefirst SG by 1 subcarrier index, e.g., from “k” to “k+1;” the third SG ischosen to hop “upwardly” from the second SG by 6 subcarrier indexes,e.g., from “k+1” to “k+7;” the fourth SG is chosen to hop “downwardly”from the third SG by 1 subcarrier index, e.g., from “k+7” to “k+6.” Thefifth SG with a subcarrier index, e.g., subcarrier index “n,” is chosen,wherein n is not limited by the subcarrier index k and is 7 in the aboveexample; the sixth SG is chosen to hop “upwardly” from the fifth SG by 1subcarrier index, e.g., from “n” to “n+1;” the seventh SG is chosen tohop “downwardly” from the sixth SG by 6 subcarrier indexes, e.g., from“n+1” to “n−5;” the eighth SG is chosen to hop “downwardly” from theseventh SG by 1 subcarrier index, e.g., from “n−5” to “n−6.”

The Preamble format 440 illustrated in FIG. 4C is substantially similarto the Preamble format 420 except that the sub-group 403 is selected.Thus, the Preamble format 440 is discussed briefly as follows. In thePreamble format 440, the first SG is with a subcarrier index, e.g.,subcarrier index “k,” wherein k is randomly chosen; the second SG hops“upwardly” from the first SG by 1 subcarrier index, e.g., from “k” to“k+1;” the third SG hops “downwardly” from the second SG by 6 subcarrierindexes, e.g., from “k+1” to “k−5;” the fourth SG hops “downwardly” fromthe third SG by 1 subcarrier index, e.g., from “k−5” to “k−6.” The fifthSG is with a subcarrier index, e.g., subcarrier index “n,” wherein n isnot limited by the subcarrier index k; the sixth SG hops “upwardly” fromthe fifth SG by 1 subcarrier index, e.g., from “n” to “n+1;” the seventhSG hops “upwardly” from the sixth SG by 6 subcarrier indexes, e.g., from“n+1” to “n+7;” the eighth SG hops “downwardly” from the seventh SG by 1subcarrier index, e.g., from “n+7” to “n+6.”

It is noted that, in such an embodiment, at least two upward frequencyhoppings and at least two downward frequency hoppings that each crossesover 1 subcarrier index and at least one upward frequency hopping and atleast one downward frequency hopping that each crosses over 6 subcarrierindexes are present in each of the Preamble formats 420 and 440.Accordingly, the Preamble, using either the Preamble format 420 or 440,can follow a hopping pattern that includes a first hopping pathassociated with a first plurality of increasing subcarrier spacings,which correspond to a first plurality of increasing subcarrier indexesin the current example (e.g., from k+1 to k+7 in the format 420, fromn+1 to n+7 in format 440, etc.), a second hopping path associated with asecond plurality of decreasing subcarrier spacings, which correspond toa second plurality of decreasing subcarrier indexes in the currentexample (e.g., from n+1 to n−5 in the format 420, from k+1 to k−5 in theformat 440), a third hopping path associated with 1 increasingsubcarrier spacing (e.g., from k to k+1 in the format 420, from k to k+1in the format 440), a fourth hopping path associated with 1 decreasingsubcarrier spacing (e.g., from k+7 to k+6 in the format 420, from k−5 tok−6 in the format 440), a fifth hopping path associated with 1increasing subcarrier spacing (e.g., from n to n+1 in the format 420,from n to n+1 in the format 440), and a sixth hopping path associatedwith 1 decreasing subcarrier spacing (e.g., from n−5 to n−6 in theformat 420, from n+7 to n+6 in the format 440). Further, in someembodiments, respective frequency intervals (or typically known asfrequency hopping distances) of the first and second hopping paths maybe equal to each other. In some alternative embodiments, such frequencyintervals of the first and second hopping paths may be each of anintegral times or a fractional times a respective subcarrier spacing(e.g., 3.75 kHz). Alternatively stated, the first plurality ofincreasing subcarrier spacings and the second plurality of decreasingsubcarrier spacings may be each an integral times or a fractional timesthe 3.75 kHz subcarrier spacing in the current example.

In another embodiment, when an SG is defined based on the subcarrierspacing of 3.75 kHz (e.g., the SG 302), another disclosed Preambleformat, which will be discussed with respect to FIGS. 5B and 5C, isdecided based on a respective pre-defined SG map 500 as illustrated inFIG. 5A. In the illustrated embodiment of FIG. 5A, the SG map 500includes 72 SGs, each of which may be implemented by the SG 302. Morespecifically, in some embodiments, the SG map 500 extends across 6 SGswith corresponding time durations (9.6 ms) in the time domain, andacross 12 SGs, i.e., 12 contiguous subcarrier spacings in the frequencydomain (180 kHz), respectively. In the time domain, each SG isassociated with a respective SG index (e.g., SG index 1, 2, 3, 4, 5, or6); and in the frequency domain, each SG is associated with a respectivesubcarrier index (e.g., subcarrier index 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, or 11).

According to some embodiments, the SG map 500 are divided into twosub-groups 501 and 503, which are filled with a dotted pattern and adiagonal stripes pattern, respectively, as shown in FIG. 5A. In someembodiments, in the SG map 500, the SGs sharing a common SG index (i.e.,along a same column of the SG map 500) has a half that belongs to thesub-group 501 and the other half that belongs to the sub-group 503.Further, along one of the columns of the SG map 500, each of the SGs,belonging to the sub-group 501, is associated with a respective PRACHindex that is selected from one of 0, 1, 2, 3, 4, and 5; and each of theSGs, belonging to the sub-group 503, is associated with a respectivePRACH index that is selected from one of 0, 1, 2, 3, 4, and 5. In someembodiments, respective distributions of the PRACH indexes in terms ofSG index/subcarrier index within each sub-group are pre-defined, asprovided below.

For example, along the column with the SG index 1, the SGs within thesub-group 501 with the subcarrier indexes 0, 1, 2, 3, 4, and 5 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; and the SGs within the sub-group 503 with the subcarrierindexes 6, 7, 8, 9, 10, and 11 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively. Along the column with the SGindex 2, the SGs within the sub-group 501 with the subcarrier indexes 0,1, 2, 3, 4, and 5 are associated with respective PRACH indexes 1, 0, 3,2, 5, and 4, respectively; and the SGs within the sub-group 503 with thesubcarrier indexes 6, 7, 8, 9, 10, and 11 are associated with respectivePRACH indexes 1, 0, 3, 2, 5, and 4, respectively. Along the column withthe SG index 3, the SGs within the sub-group 503 with the subcarrierindexes 0, 1, 2, 3, 4, and 5 are associated with respective PRACHindexes 1, 0, 3, 2, 5, and 4, respectively; and the SGs within thesub-group 501 with the subcarrier indexes 6, 7, 8, 9, 10, and 11 areassociated with respective PRACH indexes 1, 0, 3, 2, 5, and 4,respectively. Along the column with the SG index 4, the SGs within thesub-group 503 with the subcarrier indexes 0, 1, 2, 3, 4, and 5 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; and the SGs within the sub-group 501 with the subcarrierindexes 6, 7, 8, 9, 10, and 11 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively. Along the column with the SGindex 5, the SGs within the sub-group 501 with the subcarrier indexes 0,1, 2, 3, 4, and 5 are associated with respective PRACH indexes 0, 1, 2,3, 4, and 5, respectively; and the SGs within the sub-group 503 with thesubcarrier indexes 6, 7, 8, 9, 10, and 11 are associated with respectivePRACH indexes 0, 1, 2, 3, 4, and 5, respectively. Along the column withthe SG index 6, the SGs within the sub-group 501 with the subcarrierindexes 0, 1, 2, 3, 4, and 5 are associated with respective PRACHindexes 1, 0, 3, 2, 5, and 4, respectively; and the SGs within thesub-group 503 with the subcarrier indexes 6, 7, 8, 9, 10, and 11 areassociated with respective PRACH indexes 1, 0, 3, 2, 5, and 4,respectively.

The above-discussed distribution of PRACH indexes of the SG map 500 ispre-defined in accordance with a second frequency/time hopping rule thatcan be used by a UE (e.g., 104 of FIG. 1) to send a Preamble to a BS(e.g., 102 of FIG. 1) for initiating a random access procedure. Inaccordance with some embodiments of the present disclosure, the secondfrequency/time hopping rule indicates that the Preamble is sent using atleast 6 SGs (i.e., the Preamble includes at least 6 SGs), each of whichis selected from a respective SG index. Further, the secondfrequency/time hopping rule indicates that either the sub-group 501 or503 is selected, and subsequently, a first SG can be randomly chosenfrom the first column (i.e., the column with the SG index 1) of the SGmap 500 within the selected sub-group. Next, subsequent (e.g.,remaining) SGs of the at least 6 SGs are each chosen from a respectivecolumn (i.e., the columns with SG indexes 2, 3, 4, 5, and 6) within theselected sub-group, wherein all 6 SGs share a same PRACH index. In analternative embodiment, the second frequency/time hopping rule includes:randomly selecting an SG from the first column as the first SG of the atleast 6 SGs; based on a respective sub-carrier index of the randomlyselected SG in the first column, determining which of the sub-groups andwhich PRACH index to be used for the remaining 5 SGs of the at least 6SGs. As such, the Preamble follows a corresponding Preamble format whenthe second frequency/time hopping rule is applied.

In an embodiment, when the second frequency/time hopping rule is appliedand the Preamble is sent using more than 6 SGs, e.g., 12 SGs, respectivesubcarrier indexes of a first SG of a first set of 6 SGs and a first SGof a second set of 6 SGs may be randomly selected.

FIGS. 5B and 5C provide two exemplary Preamble formats 520 and 540 thatcan be used by a Preamble including at least 6 SGs when the secondfrequency/time hopping rule is applied. As mentioned above, one of thesub-groups 501 and 503 is first selected. In FIG. 5B, the sub-group 501is selected. Next, a first SG within the sub-group 501 with a subcarrierindex, e.g., subcarrier index “k,” is chosen, wherein k is randomlychosen, and the remaining SGs (second, third, fourth, fifth, and sixthSGs) are chosen as follows. The second SG is chosen to hop “upwardly”from the first SG by 1 subcarrier index, e.g., from “k” to “k+1;” thethird SG is chosen to hop “upwardly” from the second SG by 6 subcarrierindexes, e.g., from “k+1” to “k+7;” the fourth SG is chosen to hop“downwardly” from the third SG by 1 subcarrier index, e.g., from “k+7”to “k+6;” the fifth SG is chosen to hop “downwardly” from the fourth SGby 6 subcarrier indexes, e.g., from “k+6” to “k;” and the sixth SG ischosen to hop “upwardly” from the fifth SG by 1 subcarrier index, e.g.,from “k” to “k+1.”

The Preamble format 540 illustrated in FIG. 5C is substantially similarto the Preamble format 520 except that the sub-group 503 is chosen.Thus, the Preamble format 540 is discussed briefly as follows. In thePreamble format 540, the first SG is with a subcarrier index, e.g.,subcarrier index “k,” wherein k is randomly chosen; the second SG hops“upwardly” from the first SG by 1 subcarrier index, e.g., from “k” to“k+1;” the third SG hops “downwardly” from the second SG by 6 subcarrierindexes, e.g., from “k+1” to “k−5;” the fourth SG hops “downwardly” fromthe third SG by 1 subcarrier index, e.g., from “k−5” to “k−6;” the fifthSG hops “upwardly” from the fourth SG by 6 subcarrier indexes, e.g.,from “k−6” to “k;” the sixth SG hops “upwardly” from the fifth SG by 1subcarrier index, e.g., from “k” to “k+1.”

It is noted that, in such an embodiment, at least two upward frequencyhoppings, at least one downward frequency hopping that each crosses over1 subcarrier index and at least one upward frequency hopping and atleast one downward frequency hopping that each crosses over 6 subcarrierindexes are present in each of the Preamble formats 520 and 540.Accordingly, the Preamble, using either the Preamble format 520 or 540,can follow a hopping pattern that includes a first hopping pathassociated with a first plurality of increasing subcarrier spacings,which correspond to a first plurality of increasing subcarrier indexesin the current example (e.g., from k+1 to k+7 in the format 520, fromk−6 to k in format 540, etc.), a second hopping path associated with asecond plurality of decreasing subcarrier spacings, which correspond toa second plurality of decreasing subcarrier indexes in the currentexample (e.g., from k+6 to k in the format 520, from k+1 to k−5 in theformat 540), a third hopping path associated with 1 increasingsubcarrier spacing (e.g., from k to k+1 in the format 520, from k to k+1in the format 540), a fourth hopping path associated with 1 decreasingsubcarrier spacing (e.g., from k+7 to k+6 in the format 520, from k−5 tok−6 in the format 540), and a fifth hopping path associated with 1increasing subcarrier spacing (e.g., from k to k+1 in the format 520,from k to k+1 in the format 540). Further, in some embodiments,respective frequency intervals (or typically known as frequency hoppingdistances) of the first and second hopping paths may be equal to eachother. In some alternative embodiments, such frequency intervals of thefirst and second hopping paths may be each of an integral times or afractional times a respective subcarrier spacing (e.g., 3.75 kHz).Alternatively stated, the first plurality of increasing subcarrierspacings and the second plurality of decreasing subcarrier spacings maybe each an integral times or a fractional times the 3.75 kHz subcarrierspacing in the current example.

In yet another embodiment, when an SG is defined based on the subcarrierspacing of 1.25 kHz (e.g., the SG 304), a disclosed Preamble format,which will be discussed with respect to FIG. 6B, is decided based on apre-defined SG map 600 as illustrated in FIG. 6A. In the illustratedembodiment of FIG. 6A, the SG map 600 includes 168 SGs, each of whichmay be implemented by the SG 304. More specifically, in someembodiments, the SG map 600 includes two portions 600-1 and 600-2 spacedfrom each other by 12 contiguous subcarrier spacings in the frequencydomain, and each of the portions 600-1 and 600-2 extends across 7 SGswith corresponding time durations (16.8 ms) in the time domain andacross 12 SGs, i.e., 12 subcarrier spacings, (60 kHz) in the frequencydomain, respectively. In the time domain, each SG is associated with arespective SG index (e.g., SG index 1, 2, 3, 4, 5, 6, or 7); and in thefrequency domain, each SG is associated with a respective subcarrierindex (e.g., subcarrier index 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 24,25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35). Because of the 12contiguous subcarrier spacings between the portions 600-1 and 600-2, itis noted that subcarrier indexes between 11 and 24 are not contiguous.

According to some embodiments, the SG map 600 are divided into foursub-groups 601, 603, 605, and 607, which are filled with a dottedpattern, a diagonal stripes pattern, a vertical stripes pattern, and ahorizontal stripes pattern, respectively, as shown in FIG. 6A. In someembodiments, in the SG map 600, the SGs sharing a common SG index (i.e.,along a same column of the SG map 600) has a first quarter that belongsto the sub-group 601, a second quarter that belongs to the sub-group603, a third quarter that belongs to the sub-group 605, and a fourthquarter that belongs to the sub-group 607. Further, along one of thecolumns of the SG map 600, each of the SGs, belonging to the sub-group601, is associated with a respective PRACH (Physical Random AccessChannel) index that is selected from one of 0, 1, 2, 3, 4, and 5; eachof the SGs, belonging to the sub-group 603, is associated with arespective PRACH index that is selected from one of 0, 1, 2, 3, 4, and5; each of the SGs, belonging to the sub-group 605, is associated with arespective PRACH index that is selected from one of 0, 1, 2, 3, 4, and5; and each of the SGs, belonging to the sub-group 607, is associatedwith a respective PRACH index that is selected from one of 0, 1, 2, 3,4, and 5. In some embodiments, respective distributions of the PRACHindexes in terms of SG index/subcarrier index within each sub-group arepre-defined, as provided below.

For example, along the column with the SG index 1, the SGs within thesub-group 601 with the subcarrier indexes 0, 1, 2, 3, 4, and 5 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; the SGs within the sub-group 603 with the subcarrierindexes 6, 7, 8, 9, 10, and 11 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively; the SGs within the sub-group605 with the subcarrier indexes 24, 25, 26, 27, 28, and 29 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; the SGs within the sub-group 607 with the subcarrierindexes 30, 31, 32, 33, 34, and 35 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively. Similarly, along each ofother columns of the SG map 600, the SGs belonging to each sub-group areeach associated with a corresponding PRACH index in terms of thesub-carrier index, as illustrated in FIG. 6A. Thus, for purposes ofbrevity, discussions of the PRACH indexes for the SGs along columns withSG indexes 2-7 are not repeated here.

The above-discussed distribution of PRACH indexes of the SG map 600 ispre-defined in accordance with a third frequency/time hopping rule thatcan be used by a UE (e.g., 104 of FIG. 1) to send a Preamble to a BS(e.g., 102 of FIG. 1) for initiating a random access procedure. Inaccordance with some embodiments of the present disclosure, the thirdfrequency/time hopping rule indicates that the Preamble is sent using atleast 7 SGs (i.e., the Preamble includes at least 7 SGs), each of whichis selected from a respective SG index. Further, the thirdfrequency/time hopping rule indicates that one of the sub-groups 601,603, 605, and 607 is selected, and subsequently, a first SG can berandomly chosen from the first column (i.e., the column with the SGindex 1) of the SG map 600 within the selected sub-group. Next,subsequent (e.g., remaining) SGs of the at least 7 SGs are each chosenfrom a respective column (i.e., the columns with SG indexes 2, 3, 4, 5,6, and 7) within the selected sub-group, wherein all 7 SGs share a samePRACH index. In an alternative embodiment, the third frequency/timehopping rule includes: randomly selecting an SG from the first column asthe first SG of the at least 7 SGs; based on a respective sub-carrierindex of the randomly selected SG in the first column, determining whichof the sub-groups and which PRACH index to be used for the remaining 6SGs of the at least 7 SGs. As such, the Preamble follows a correspondingPreamble format when the third frequency/time hopping rule is applied.

In an embodiment, when the third frequency/time hopping rule is appliedand the Preamble is sent using more than 7 SGs, e.g., 14 SGs, respectivesubcarrier indexes of a first SG of a first set of 7 SGs and a first SGof a second set of 7 SGs may be randomly selected.

FIG. 6B provides an exemplary Preamble format 620 that can be used by aPreamble including at least 7 SGs when the third frequency/time hoppingrule is applied. As mentioned above, one of the sub-groups 601, 603,605, and 607 is selected. In FIG. 6B, the sub-group 601 is selected, forexample. Next, a first SG within the sub-group 601 with a subcarrierindex, e.g., subcarrier index “k,” is chosen, wherein k is randomlychosen, and the remaining SGs (second, third, fourth, fifth, sixth, andseventh SGs) are chosen as follows. The second SG is chosen to hop“upwardly” from the first SG by 1 subcarrier index, e.g., from “k” to“k+1;” the third SG is chosen to hop “upwardly” from the second SG by 6subcarrier indexes, e.g., from “k+1” to “k+7;” the fourth SG is chosento hop “downwardly” from the third SG by 6 subcarrier indexes, e.g.,from “k+7” to “k+1;” the fifth SG is chosen to hop “upwardly” from thefourth SG by 24 subcarrier indexes, e.g., from “k+1” to “k+25;” thesixth SG is chosen to hop “downwardly” from the fifth SG by 24subcarrier indexes, e.g., from “k+25” to “k+1;” and the seventh SG ischosen to hop “downwardly” from the sixth SG by 1 subcarrier index,e.g., from “k+1” to “k.”

It is noted that, in such an embodiment, at least one upward frequencyhopping and at least one downward frequency hoppings that each crossesover 1 subcarrier index, at least two upward frequency hoppings thateach crosses over 6 and 24 subcarrier indexes, respectively, and atleast two downward frequency hoppings that each crosses over 6 and 24subcarrier indexes, respectively, are present in the Preamble format620. Accordingly, the Preamble, using the Preamble format 620, canfollow a hopping pattern that includes a first hopping path associatedwith a first plurality of increasing subcarrier indexes (e.g., from k+1to k+7), a second hopping path associated with a second plurality ofdecreasing subcarrier indexes (e.g., from k+7 to k+1), a third hoppingpath associated with a third plurality of increasing subcarrier indexes(e.g., from k+1 to k+25), a fourth hopping path associated with a fourthplurality of decreasing subcarrier indexes (e.g., from k+25 to k+1), afifth hopping path associated with 1 increasing subcarrier spacing(e.g., from k to k+1 in the format 620), and a sixth hopping pathassociated with 1 decreasing subcarrier spacing (e.g., from k+1 to k inthe format 620).

Further, in some embodiments, respective frequency intervals (ortypically known as frequency hopping distances) of the first and secondhopping paths may be equal to each other, and respective frequencyintervals of the third and fourth hopping paths may be equal to eachother. In some alternative embodiments, such frequency intervals of thefirst, second, third, and fourth hopping paths may be each of anintegral times or a fractional times a respective subcarrier spacing(e.g., 1.25 kHz). Alternatively stated, the first plurality ofincreasing subcarrier spacings, the second plurality of decreasingsubcarrier spacings, the third plurality of increasing subcarrierspacings, and the fourth plurality of decreasing subcarrier spacings maybe each an integral times or a fractional times the 1.25 kHz subcarrierspacing in the current example.

Still in yet another embodiment, when an SG is defined based on thesubcarrier spacing of 1.25 kHz (e.g., the SG 304), another disclosedPreamble format, which will be discussed with respect to FIG. 7B, isdecided based on a pre-defined SG map 700 as illustrated in FIG. 7A. Inthe illustrated embodiment of FIG. 7A, the SG map 700 includes 168 SGs,each of which may be implemented by the SG 304. More specifically, insome embodiments, the SG map 700 includes two portions 700-1 and 700-2spaced from each other by 12 contiguous subcarrier spacings in thefrequency domain, and each of the portions 700-1 and 700-2 extendsacross 7 SGs with corresponding time durations (16.8 ms) in the timedomain and across 12 SGs, i.e., 12 subcarrier spacings, (60 kHz) in thefrequency domain, respectively. In the time domain, each SG isassociated with a respective SG index (e.g., SG index 1, 2, 3, 4, 5, 6,or 7); and in the frequency domain, each SG is associated with arespective subcarrier index (e.g., subcarrier index 0, 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35).Because of the 12 contiguous subcarrier spacings between the portions700-1 and 700-2, it is noted that subcarrier indexes between 11 and 24are not contiguous.

According to some embodiments, the SG map 700 are divided into foursub-groups 701, 703, 705, and 707, which are filled with a dottedpattern, a diagonal stripes pattern, a vertical stripes pattern, and ahorizontal stripes pattern, respectively, as shown in FIG. 7A. In someembodiments, in the SG map 700, the SGs sharing a common SG index (i.e.,along a same column of the SG map 700) has a first quarter that belongsto the sub-group 701, a second quarter that belongs to the sub-group703, a third quarter that belongs to the sub-group 705, and a fourthquarter that belongs to the sub-group 707. Further, along one of thecolumns of the SG map 700, each of the SGs, belonging to the sub-group701, is associated with a respective PRACH (Physical Random AccessChannel) index that is selected from one of 0, 1, 2, 3, 4, and 5; eachof the SGs, belonging to the sub-group 703, is associated with arespective PRACH index that is selected from one of 0, 1, 2, 3, 4, and5; each of the SGs, belonging to the sub-group 705, is associated with arespective PRACH index that is selected from one of 0, 1, 2, 3, 4, and5; and each of the SGs, belonging to the sub-group 707, is associatedwith a respective PRACH index that is selected from one of 0, 1, 2, 3,4, and 5. In some embodiments, respective distributions of the PRACHindexes in terms of SG index/subcarrier index within each sub-group arepre-defined, as provided below.

For example, along the column with the SG index 1, the SGs within thesub-group 701 with the subcarrier indexes 0, 1, 2, 3, 4, and 5 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; the SGs within the sub-group 703 with the subcarrierindexes 6, 7, 8, 9, 10, and 11 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively; the SGs within the sub-group705 with the subcarrier indexes 24, 25, 26, 27, 28, and 29 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; the SGs within the sub-group 707 with the subcarrierindexes 30, 31, 32, 33, 34, and 35 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively. Similarly, along each ofother columns of the SG map 700, the SGs belonging to each sub-group areeach associated with a corresponding PRACH index in terms of thesub-carrier index, as illustrated in FIG. 7A. Thus, for purposes ofbrevity, discussions ofthe PRACH indexes for the SGs along columns withSG indexes 2-7 are not repeated here.

The above-discussed distribution of PRACH indexes of the SG map 700 ispre-defined in accordance with a fourth frequency/time hopping rule thatcan be used by a UE (e.g., 104 of FIG. 1) to send a Preamble to a BS(e.g., 102 of FIG. 1) for initiating a random access procedure. Inaccordance with some embodiments of the present disclosure, the fourthfrequency/time hopping rule indicates that the Preamble is sent using atleast 7 SGs (i.e., the Preamble includes at least 7 SGs), each of whichis selected from a respective SG index. Further, the fourthfrequency/time hopping rule indicates that one of the sub-groups 701,703, 705, and 707 is selected, and subsequently, a first SG can berandomly chosen from the first column (i.e., the column with the SGindex 1) of the SG map 700 within the selected sub-group. Next,subsequent (e.g., remaining) SGs of the at least 7 SGs are each chosenfrom a respective column (i.e., the columns with SG indexes 2, 3, 4, 5,6, and 7) within the selected sub-group, wherein all 7 SGs share a samePRACH index. In an alternative embodiment, the fourth frequency/timehopping rule includes: randomly selecting an SG from the first column asthe first SG of the at least 7 SGs; based on a respective sub-carrierindex of the randomly selected SG in the first column, determining whichof the sub-groups and which PRACH index to be used for the remaining 6SGs of the at least 7 SGs. As such, the Preamble follows a correspondingPreamble format when the fourth frequency/time hopping rule is applied.

In an embodiment, when the fourth frequency/time hopping rule is appliedand the Preamble is sent using more than 7 SGs, e.g., 14 SGs, respectivesubcarrier indexes of a first SG of a first set of 7 SGs and a first SGof a second set of 7 SGs may be randomly selected.

FIG. 7B provides an exemplary Preamble format 720 that can be used by aPreamble including at least 7 SGs when the fourth frequency/time hoppingrule is applied. As mentioned above, one of the sub-groups 701, 703,705, and 707 is selected. In FIG. 7B, the sub-group 701 is selected, forexample. Next, a first SG within the sub-group 701 with a subcarrierindex, e.g., subcarrier index “k,” is chosen, wherein k is randomlychosen, and the remaining SGs (second, third, fourth, fifth, sixth, andseventh SGs) are chosen as follows. The second SG is chosen to hop“upwardly” from the first SG by 1 subcarrier index, e.g., from “k” to“k+1;” the third SG is chosen to hop “upwardly” from the second SG by 6subcarrier indexes, e.g., from “k+1” to “k+7;” the fourth SG is chosento hop “downwardly” from the third SG by 1 subcarrier index, e.g., from“k+7” to “k+6;” the fifth SG is chosen to hop “downwardly” from thefourth SG by 6 subcarrier indexes, e.g., from “k+6” to “k;” the sixth SGis chosen to hop “upwardly” from the fifth SG by 24 subcarrier indexes,e.g., from “k” to “k+24;” and the seventh SG is chosen to hop“downwardly” from the sixth SG by 24 subcarrier indexes, e.g., from“k+24” to “k.”

It is noted that, in such an embodiment, at least one upward frequencyhopping and at least one downward frequency hoppings that each crossesover 1 subcarrier index, at least two upward frequency hoppings thateach crosses over 6 and 24 subcarrier indexes, respectively, and atleast two downward frequency hoppings that each crosses over 6 and 24subcarrier indexes, respectively, are present in the Preamble format720. Accordingly, the Preamble, using the Preamble format 720, canfollow a hopping pattern that includes a first hopping path associatedwith a first plurality of increasing subcarrier indexes (e.g., from k+1to k+7), a second hopping path associated with a second plurality ofdecreasing subcarrier indexes (e.g., from k+6 to k), a third hoppingpath associated with a third plurality of increasing subcarrier indexes(e.g., from k to k+24), a fourth hopping path associated with a fourthplurality of decreasing subcarrier indexes (e.g., from k+24 to k), and afifth hopping path associated with 1 increasing subcarrier spacing(e.g., from k to k+1 in the format 720), and a sixth hopping pathassociated with 1 decreasing subcarrier spacing (e.g., from k+7 to k+6in the format 720).

Further, in some embodiments, respective frequency intervals (ortypically known as frequency hopping distances) of the first and secondhopping paths may be equal to each other, and respective frequencyintervals of the third and fourth hopping paths may be equal to eachother. In some alternative embodiments, such frequency intervals of thefirst, second, third, and fourth hopping paths may be each of anintegral times or a fractional times a respective subcarrier spacing(e.g., 1.25 kHz). Alternatively stated, the first plurality ofincreasing subcarrier spacings, the second plurality of decreasingsubcarrier spacings, the third plurality of increasing subcarrierspacings, and the fourth plurality of decreasing subcarrier spacings maybe each an integral times or a fractional times the 1.25 kHz subcarrierspacing in the current example.

Still in yet another embodiment, when an SG is defined based on thesubcarrier spacing of 1.25 kHz (e.g., the SG 304), yet another disclosedPreamble format, which will be discussed with respect to FIG. 8B, isdecided based on a pre-defined SG map 800 as illustrated in FIG. 8A. Inthe illustrated embodiment of FIG. 8A, the SG map 800 includes 240 SGs,each of which may be implemented by the SG 304. More specifically, insome embodiments, the SG map 800 includes two portions 800-1 and 800-2spaced from each other by 12 contiguous subcarrier spacings in thefrequency domain, and each of the portions 800-1 and 800-2 extendsacross 10 SGs with corresponding time durations (24 ms) in the timedomain and across 12 SGs, i.e., 12 subcarrier spacings, (60 kHz) in thefrequency domain, respectively. In the time domain, each SG isassociated with a respective SG index (e.g., SG index 1, 2, 3, 4, 5, 6,7, 8, 9, or 10); and in the frequency domain, each SG is associated witha respective subcarrier index (e.g., subcarrier index 0, 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 11, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35).Because of the 12 contiguous subcarrier spacings between the portions800-1 and 800-2, it is noted that subcarrier indexes between 11 and 24are not contiguous.

According to some embodiments, the SG map 800 are divided into foursub-groups 801, 803, 805, and 807, which are filled with a dottedpattern, a diagonal stripes pattern, a vertical stripes pattern, and ahorizontal stripes pattern, respectively, as shown in FIG. 8A. In someembodiments, in the SG map 800, the SGs sharing a common SG index (i.e.,along a same column of the SG map 800) has a first quarter that belongsto the sub-group 801, a second quarter that belongs to the sub-group803, a third quarter that belongs to the sub-group 805, and a fourthquarter that belongs to the sub-group 807. Further, along one of thecolumns of the SG map 800, each of the SGs, belonging to the sub-group801, is associated with a respective PRACH (Physical Random AccessChannel) index that is selected from one of 0, 1, 2, 3, 4, and 5; eachof the SGs, belonging to the sub-group 703, is associated with arespective PRACH index that is selected from one of 0, 1, 2, 3, 4, and5; each of the SGs, belonging to the sub-group 805, is associated with arespective PRACH index that is selected from one of 0, 1, 2, 3, 4, and5; and each of the SGs, belonging to the sub-group 807, is associatedwith a respective PRACH index that is selected from one of 0, 1, 2, 3,4, and 5. In some embodiments, respective distributions of the PRACHindexes in terms of SG index/subcarrier index within each sub-group arepre-defined, as provided below.

For example, along the column with the SG index 1, the SGs within thesub-group 801 with the subcarrier indexes 0, 1, 2, 3, 4, and 5 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; the SGs within the sub-group 803 with the subcarrierindexes 6, 7, 8, 9, 10, and 11 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively; the SGs within the sub-group805 with the subcarrier indexes 24, 25, 26, 27, 28, and 29 areassociated with respective PRACH indexes 0, 1, 2, 3, 4, and 5,respectively; the SGs within the sub-group 807 with the subcarrierindexes 30, 31, 32, 33, 34, and 35 are associated with respective PRACHindexes 0, 1, 2, 3, 4, and 5, respectively. Similarly, along each ofother columns of the SG map 800, the SGs belonging to each sub-group areeach associated with a corresponding PRACH index in terms of thesub-carrier index, as illustrated in FIG. 8A. Thus, for purposes ofbrevity, discussions of the PRACH indexes for the SGs along columns withSG indexes 2-10 are not repeated here.

The above-discussed distribution of PRACH indexes of the SG map 800 ispre-defined in accordance with a fifth frequency/time hopping rule thatcan be used by a UE (e.g., 104 of FIG. 1) to send a Preamble to a BS(e.g., 102 of FIG. 1) for initiating a random access procedure. Inaccordance with some embodiments of the present disclosure, the fifthfrequency/time hopping rule indicates that the Preamble is sent using atleast 10 SGs (i.e., the Preamble includes at least 10 SGs), each ofwhich is selected from a respective SG index. Further, the fifthfrequency/time hopping rule indicates that one of the sub-groups 801,803, 805, and 807 is selected, and subsequently, a first SG can berandomly chosen from the first column (i.e., the column with the SGindex 1) of the SG map 800 within the selected sub-group. Next,subsequent (e.g., remaining) SGs of the at least 10 SGs are each chosenfrom a respective column (i.e., the columns with SG indexes 2, 3, 4, 5,6, 7, 8, 9, and 10) within the selected sub-group, wherein all 10 SGsshare a same PRACH index. In an alternative embodiment, the fifthfrequency/time hopping rule includes: randomly selecting an SG from thefirst column as the first SG of the at least 10 SGs; based on arespective sub-carrier index of the randomly selected SG in the firstcolumn, determining which of the sub-groups and which PRACH index to beused for the remaining 9 SGs of the at least 10 SGs. As such, thePreamble follows a corresponding Preamble format when the fifthfrequency/time hopping rule is applied.

In an embodiment, when the fifth frequency/time hopping rule is appliedand the Preamble is sent using more than 10 SGs, e.g., 20 SGs,respective subcarrier indexes of a first SG of a first set of 10 SGs anda first SG of a second set of 10 SGs may be randomly selected.

FIG. 8B provides an exemplary Preamble format 820 that can be used by aPreamble including at least 10 SGs when the fifth frequency/time hoppingrule is applied. As mentioned above, one of the sub-groups 801, 803,805, and 807 is selected. In FIG. 8B, the sub-group 801 is selected, forexample. Next, a first SG within the sub-group 801 with a subcarrierindex, e.g., subcarrier index “k,” is chosen, wherein k is randomlychosen, and the remaining SGs (second, third, fourth, fifth, sixth,seventh, ninth, and tenth SGs) are chosen as follows. The second SG ischosen to hop “upwardly” from the first SG by 1 subcarrier index, e.g.,from “k” to “k+1;” the third SG is chosen to hop “upwardly” from thesecond SG by 6 subcarrier indexes, e.g., from “k+1” to “k+7;” the fourthSG is chosen to hop “downwardly” from the third SG by 1 subcarrierindex, e.g., from “k+7” to “k+6;” the fifth SG is chosen to hop“upwardly” from the fourth SG by 24 subcarrier indexes, e.g., from “k+6”to “k+30;” the sixth SG is chosen to hop “upwardly” from the fifth SG by1 subcarrier index, e.g., from “k+30” to “k+31;” the seventh SG ischosen to hop “downwardly” from the sixth SG by 6 subcarrier indexes,e.g., from “k+31” to “k+25;” the eighth SG is chosen to hop “downwardly”from the seventh SG by 1 subcarrier index, e.g., from “k+25” to “k+24;”the ninth SG is chosen to hop “downwardly” from the eighth SG by 24subcarrier indexes, e.g., from “k+24” to “k;” and the tenth SG is chosento hop “upwardly” from the ninth SG by 1 subcarrier index, e.g., from“k” to “k+1.”

It is noted that, in such an embodiment, at least three upward frequencyhoppings and at least two downward frequency hoppings that each crossesover 1 subcarrier index, at least two upward frequency hoppings thateach crosses over 6 and 24 subcarrier indexes, respectively, and atleast two downward frequency hoppings that each crosses over 6 and 24subcarrier indexes, respectively, are present in the Preamble format820. Accordingly, the Preamble, using the Preamble format 820, canfollow a hopping pattern that includes a first hopping path associatedwith a first plurality of increasing subcarrier indexes (e.g., from k+1to k+7), a second hopping path associated with a second plurality ofincreasing subcarrier indexes (e.g., from k+6 to k+30), a third hoppingpath associated with a third plurality of decreasing subcarrier indexes(e.g., from k+31 to k+25), a fourth hopping path associated with afourth plurality of decreasing subcarrier indexes (e.g., from k+24 tok), a fifth hopping path associated with 1 increasing subcarrier spacing(e.g., from k to k+1 in the format 820), a sixth hopping path associatedwith 1 decreasing subcarrier spacing (e.g., from k+7 to k+6 in theformat 820), a seventh hopping path associated with 1 increasingsubcarrier spacing (e.g., from k+30 to k+31 in the format 820), aneighth hopping path associated with 1 decreasing subcarrier spacing(e.g., from k+25 to k+24 in the format 820), and a ninth hopping pathassociated with 1 increasing subcarrier spacing (e.g., from k to k+1 inthe format 820).

Further, in some embodiments, respective frequency intervals (ortypically known as frequency hopping distances) of the first and thirdhopping paths may be equal to each other, and respective frequencyintervals of the second and fourth hopping paths may be equal to eachother. In some alternative embodiments, such frequency intervals of thefirst, second, third, and fourth hopping paths may be each of anintegral times or a fractional times a respective subcarrier spacing(e.g., 1.25 kHz). Alternatively stated, the first plurality ofincreasing subcarrier spacings, the second plurality of increasingsubcarrier spacings, the third plurality of decreasing subcarrierspacings, and the fourth plurality of decreasing subcarrier spacings maybe each an integral times or a fractional times the 1.25 kHz subcarrierspacing in the current example.

Although, in the above discussions, the Preamble format (e.g., 420, 440,520, 540, 620, 720, and 820) is directed to being used for transmittinga PRACH (Physical Random Access Channel) signal, it is noted that eachof the above-discussed Preamble format can be used for transmitting anuplink signal (i.e., a signal transmitted from the UE 104 to the BS 102)while remaining within the scope of the present disclosure. For example,each of the above-discussed Preamble format can be used for transmittinga Positioning Reference signal, a Scheduling Request Reference signal,or the like.

As mentioned above, each Preamble format includes a plurality of SGs(symbol groups), and each SG includes a plurality of CP and symbols. Insome alternative embodiments, in order to further mitigate interferencebetween neighboring cells (e.g., neighboring cells), the presentdisclosure provides various embodiments of a method 900 in FIG. 9 toallow each symbol to carry a number/value of a respective sequence,wherein such a sequence may be one of a plurality of pre-defined and/orpre-generated random sequences. Moreover, a length of such a sequencemay be determined based on a length of a respective “symbol group set,”which will be discussed in further detail below.

In accordance with some embodiments of the present disclosure, themethod 900 starts with operation 902 in which a Preamble format isprovided. Next, the method 900 proceeds to operation 904 in whichrespective SGs of the Preamble format is grouped into one or more SGsets. The method 900 proceeds to operation 906 in which a plurality ofsequences are generated. In some embodiments, each of the plurality ofsequences has a sequence length that may be determined based on a numberof SGs included in the SG set provided in the operation 904. The method900 proceeds to operation 906 in which one of the plurality of sequencesis selected to be used for one of the one or more SG sets. The method900 proceeds to operation 908 in which symbol(s) within respectivedifferent SGs of the SG set are each assigned with a respectivedifferent value contained in the selected sequence. Various examples areprovided below to illustrate how each symbol is assigned with arespective value when the method 900 is used.

In an example, the Preamble format 420 of FIG. 4B that includes at least8 SGs is provided. Next, the at least 8 SGs are grouped into 4 SG sets.In an embodiment, two adjacent SGs are grouped into a respective SG set.For example, the first and second SGs are grouped into a first SG set(1^(st) SG set); the third and fourth SGs are grouped into a second SGset (2^(nd) SG set); the fifth and sixth SGs are grouped into a third SGset (3^(rd) SG set); and the seventh and eighth SGs are grouped into afourth SG set (4^(th) SG set). Next, a plurality of sequences aregenerated, wherein each sequence has a sequence length that isconsistent with a number of the SGs in each SG set, which is 2 in theabove example. For example, the plurality of sequences may include: {1,1}, {1, −1}, {1, j}, and {1, −j}, wherein each of the sequence has asequence length of 2, and accordingly is composed of two respectivesequence values. Next, one of the plurality of sequences is selected tobe used by one of the SG sets. For example, the sequence {1, −1} isselected to be used by the first SG set. As such, the symbols of thefirst SG of the first SG set are each assigned with one of the sequencevalues, e.g., “1,” and the symbols of the second SG of the first SG setare each assigned with the other of the sequence values, e.g., “−1.”Analogously, each of the remaining SG sets uses any of the foursequences, which can be identical to or different from the sequence usedby the first SG set. For example, {1, −1}, which is identical to the oneused by the first SG set, or one of {1, 1}, {1, j}, and {1, −j}, whichis different from the one used by the second SG set, may be used by thesecond, third, or fourth SG set.

In another example, the Preamble format 620 of FIG. 6B that includes atleast 7 SGs is provided. Next, the at least 7 SGs are grouped into 7 SGsets, each of which has one SG. Next, a plurality of sequences aregenerated, wherein each sequence a sequence length that is consistentwith a number of the SGs in each SG set, which is 1 in the aboveexample. For example, the plurality of sequences may include: {1}, {−1},{j}, and {−j}, wherein each of the sequence has a sequence length of 1,and accordingly is composed of one respective sequence value. Next, oneof the plurality of sequences is selected to be used by one of the SGsets. For example, the sequence {1} is selected to be used by a first SGset (i.e., a first SG in this example). As such, the symbols of thefirst SG set are each assigned with the sequence value of the sequence,“1.” Analogously, each of the remaining SG sets uses any of the foursequences, which can be identical to or different from the sequence usedby the first SG set.

In yet another example, the Preamble format 620 of FIG. 6B that includesat least 7 SGs is provided. Next, the at least 7 SGs are grouped into 1SG set. Next, a plurality of sequences are generated, wherein eachsequence a sequence length that is consistent with a number of the SGsin each SG set, which is 7 in the above example. The present disclosureprovides embodiments of a method to generate a plurality of sequences,each of which has a sequence length of 7. In particular, the pluralityof sequences may be generated by the following equation W,

${{W = e^{j\Delta\alpha n}},{wherein}}{{\Delta = \frac{2\pi}{N_{SG}}},{N_{SG} = 7},{\alpha \in \lbrack {0,{N_{SG} - 1}} \rbrack},{{{and}n} \in {\lbrack {0,{N_{SG} - 1}} \rbrack.}}}$

In the above equation, “n” represents an (n+1)^(th) sequence valuewithin a sequence, and “α” represents an α^(th) sequence of theplurality of sequences. The present disclosure provides embodiments ofanother method to generate a plurality of sequences, each of which has asequence length of 8. In particular, the plurality of sequences may begenerated by the following equation W,

${{W = e^{j\Delta\alpha n}},{wherein}}{{\Delta = \frac{2\pi}{N_{SG}}},{N_{SG} = 8},{\alpha \in \lbrack {0,{N_{SG} - 1}} \rbrack},{{{and}n} \in {\lbrack {0,{N_{SG} - 1}} \rbrack.}}}$

In the above equation, “n” represents an (n+1)^(th) sequence valuewithin a sequence, and “a” represents an α^(th) sequence of theplurality of sequences. As such, for each sequence with the sequencelength of 8, 7 sequence values out of the 8 sequence values are selectedto be respectively used by the 7 SG sets. In some embodiments, these 7sequence values may be the first 7 sequence values of the 8 sequencevalues, the last 7 sequence values of the 8 sequence values, or randomlyselected from the 8 sequence values.

In yet another example, the Preamble format 420 of FIG. 4B that includesat least 8 SGs is provided. The present disclosure provides embodimentsof a method to generate a plurality of sequences, each of which has asequence length of 4. In particular, the plurality of sequences may begenerated by the following equation W,

${{W = e^{j\Delta\alpha n}},{wherein}}{{\Delta = \frac{2\pi}{N_{SG}}},{N_{SG} = 4},{\alpha \in \lbrack {0,{N_{SG} - 1}} \rbrack},{{{and}n} \in {\lbrack {0,{N_{SG} - 1}} \rbrack.}}}$

In the above equation, “n” represents an (n+1)^(th) sequence valuewithin a sequence, and “a” represents an α^(th) sequence of theplurality of sequences. For example, using the above equation, aplurality of sequences with the sequence length of 4 include: {1, 1, 1,1}, {1, j, −1, −j}, {1, −1, 1, −1}, and {1, −j, −1, j}. Similar to themethod described above, the at least 8 SGs are grouped into a pluralityof SG sets, each of which has 4 adjacent SGs. And each SG set,containing 4 SGs, uses one of the plurality of sequences with 4respective different sequence values (because the sequence length is 4),to assign the 4 SGs' respective symbols with the 4 respective differentsequence values.

While various embodiments of the invention have been described above, itshould be understood that they have been presented by way of exampleonly, and not by way of limitation. Likewise, the various diagrams maydepict an example architectural or configuration, which are provided toenable persons of ordinary skill in the art to understand exemplaryfeatures and functions of the invention. Such persons would understand,however, that the invention is not restricted to the illustrated examplearchitectures or configurations, but can be implemented using a varietyof alternative architectures and configurations. Additionally, as wouldbe understood by persons of ordinary skill in the art, one or morefeatures of one embodiment can be combined with one or more features ofanother embodiment described herein. Thus, the breadth and scope of thepresent disclosure should not be limited by any of the above-describedexemplary embodiments.

It is also understood that any reference to an element herein using adesignation such as “first,” “second,” and so forth does not generallylimit the quantity or order of those elements. Rather, thesedesignations can be used herein as a convenient means of distinguishingbetween two or more elements or instances of an element. Thus, areference to first and second elements does not mean that only twoelements can be employed, or that the first element must precede thesecond element in some manner.

Additionally, a person having ordinary skill in the art would understandthat information and signals can be represented using any of a varietyof different technologies and techniques. For example, data,instructions, commands, information, signals, bits and symbols, forexample, which may be referenced in the above description can berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof.

A person of ordinary skill in the art would further appreciate that anyof the various illustrative logical blocks, modules, processors, means,circuits, methods and functions described in connection with the aspectsdisclosed herein can be implemented by electronic hardware (e.g., adigital implementation, an analog implementation, or a combination ofthe two), firmware, various forms of program or design codeincorporating instructions (which can be referred to herein, forconvenience, as “software” or a “software module), or any combination ofthese techniques. To clearly illustrate this interchangeability ofhardware, firmware and software, various illustrative components,blocks, modules, circuits, and steps have been described above generallyin terms of their functionality. Whether such functionality isimplemented as hardware, firmware or software, or a combination of thesetechniques, depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans canimplement the described functionality in various ways for eachparticular application, but such implementation decisions do not cause adeparture from the scope of the present disclosure.

Furthermore, a person of ordinary skill in the art would understand thatvarious illustrative logical blocks, modules, devices, components andcircuits described herein can be implemented within or performed by anintegrated circuit (IC) that can include a general purpose processor, adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or otherprogrammable logic device, or any combination thereof. The logicalblocks, modules, and circuits can further include antennas and/ortransceivers to communicate with various components within the networkor within the device. A general purpose processor can be amicroprocessor, but in the alternative, the processor can be anyconventional processor, controller, or state machine. A processor canalso be implemented as a combination of computing devices, e.g., acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other suitable configuration to perform the functionsdescribed herein.

If implemented in software, the functions can be stored as one or moreinstructions or code on a computer-readable medium. Thus, the steps of amethod or algorithm disclosed herein can be implemented as softwarestored on a computer-readable medium. Computer-readable media includesboth computer storage media and communication media including any mediumthat can be enabled to transfer a computer program or code from oneplace to another. A storage media can be any available media that can beaccessed by a computer. By way of example, and not limitation, suchcomputer-readable media can include RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to store desired programcode in the form of instructions or data structures and that can beaccessed by a computer.

In this document, the term “module” as used herein, refers to software,firmware, hardware, and any combination of these elements for performingthe associated functions described herein. Additionally, for purpose ofdiscussion, the various modules are described as discrete modules;however, as would be apparent to one of ordinary skill in the art, twoor more modules may be combined to form a single module that performsthe associated functions according embodiments of the invention.

Additionally, memory or other storage, as well as communicationcomponents, may be employed in embodiments of the invention. It will beappreciated that, for clarity purposes, the above description hasdescribed embodiments of the invention with reference to differentfunctional units and processors. However, it will be apparent that anysuitable distribution of functionality between different functionalunits, processing logic elements or domains may be used withoutdetracting from the invention. For example, functionality illustrated tobe performed by separate processing logic elements, or controllers, maybe performed by the same processing logic element, or controller. Hence,references to specific functional units are only references to asuitable means for providing the described functionality, rather thanindicative of a strict logical or physical structure or organization.

Various modifications to the implementations described in thisdisclosure will be readily apparent to those skilled in the art, and thegeneral principles defined herein can be applied to otherimplementations without departing from the scope of this disclosure.Thus, the disclosure is not intended to be limited to theimplementations shown herein, but is to be accorded the widest scopeconsistent with the novel features and principles disclosed herein, asrecited in the claims below.

What is claimed is:
 1. A method, comprising: receiving a resourceallocation message indicative of a plurality of resource groupsallocated for a signal; and transmitting the signal using a portion ofthe plurality of resource groups, wherein, in a frequency domain, theportion of the plurality of resource groups presents a hopping patterncomprising at least: a first hopping path that is associated withincreasing subcarrier frequency by a first plurality of frequencyspacings, and a second hopping path that is associated with decreasingsubcarrier frequency by a second plurality of frequency spacings,wherein each of the plurality of resource groups comprises one or moresymbols.
 2. The method of claim 1, wherein the signal comprises aPhysical Random Access Channel signal.
 3. The method of claim 1,wherein: the first hopping path corresponds to a first portion of theplurality of resource groups; the second hopping path corresponds to asecond portion of the plurality of resource groups; and the secondportion is different from the first portion.
 4. The method of claim 1,wherein each of the one or more symbols contains a sequence valueselected from one of a plurality of pre-defined sequences.
 5. The methodof claim 4, wherein each of the plurality of pre-defined sequences has asequence length equal to a number of resource groups in a correspondingset of resource groups.
 6. The method of claim 1, wherein respectivevalues of the first plurality of frequency spacings and the secondplurality of frequency spacings are equal to each other.
 7. The methodof claim 6, wherein the hopping pattern further comprises: a thirdhopping path that is associated with increasing subcarrier frequency bya third plurality of frequency spacings; and a fourth hopping path thatis associated with decreasing subcarrier frequency by a fourth pluralityof frequency spacings.
 8. The method of claim 7, wherein respectivevalues of the third plurality of frequency spacings and the fourthplurality of frequency spacings are equal to each other, but differentfrom the value of either the first plurality of frequency spacings orthe second plurality of frequency spacings.
 9. A method, comprising:transmitting a resource allocation message indicating a plurality ofresource groups allocated for a signal, wherein, in a frequency domain,at least a portion of the plurality of resource groups presents ahopping pattern comprising at least: a first hopping path that isassociated with increasing subcarrier frequency by a first plurality offrequency spacings, and a second hopping path that is associated withdecreasing subcarrier frequency by a second plurality of frequencyspacings, wherein each of the plurality of resource groups comprises oneor more symbols.
 10. The method of claim 9, wherein the signal comprisesa Physical Random Access Channel signal.
 11. The method of claim 9,wherein: the first hopping path corresponds to a first portion of theplurality of resource groups; the second hopping path corresponds to asecond portion of the plurality of resource groups; and the secondportion is different from the first portion.
 12. The method of claim 9,wherein each of the one or more symbols contains a sequence valueselected from one of a plurality of pre-defined sequences.
 13. Themethod of claim 12, wherein each of the plurality of pre-definedsequences has a sequence length equal to a number of resource groups ina corresponding set of resource groups.
 14. The method of claim 9,wherein respective values of the first plurality of frequency spacingsand the second plurality of frequency spacings are equal to each other.15. The method of claim 14, wherein the hopping pattern furthercomprises: a third hopping path that is associated with increasingsubcarrier frequency by a third plurality of frequency spacings; and afourth hopping path that is associated with decreasing subcarrierfrequency by a fourth plurality of frequency spacings.
 16. The method ofclaim 15, wherein respective values of the third plurality of frequencyspacings and the fourth plurality of frequency spacings are equal toeach other, but different from the value of either the first pluralityof frequency spacings or the second plurality of frequency spacings. 17.A communication node, comprising: a receiver configured to receive aresource allocation message indicative of a plurality of resource groupsallocated for a signal; and a transmitter configured to transmit thesignal using a portion of the plurality of resource groups, wherein, ina frequency domain, the portion of the plurality of resource groupspresents a hopping pattern comprising at least: a first hopping paththat is associated with increasing subcarrier frequency by a firstplurality of frequency spacings, and a second hopping path that isassociated with decreasing subcarrier frequency by a second plurality offrequency spacings, wherein each of the plurality of resource groupscomprises one or more symbols.
 18. The communication node of claim 17,wherein respective values of the first plurality of frequency spacingsand the second plurality of frequency spacings are equal to each other.19. A communication node, comprising: a transmitter configured totransmit a resource allocation message indicating a plurality ofresource groups allocated for a signal, wherein, in a frequency domain,at least a portion of the plurality of resource groups presents ahopping pattern comprising at least: a first hopping path that isassociated with increasing subcarrier frequency by a first plurality offrequency spacings, and a second hopping path that is associated withdecreasing subcarrier frequency by a second plurality of frequencyspacings, wherein each of the plurality of resource groups comprises oneor more symbols.
 20. The communication node of claim 19, whereinrespective values of the first plurality of frequency spacings and thesecond plurality of frequency spacings are equal to each other.